Institute for Molecular and Cellular Regulation National University Corporation Gunma University 生体調節研究所 概要 国立大学法人 群馬大学 Department of Molecular and Cellular Biology Department of Molecular Medicine Biosignal Genome Resource Center Metabolic Signal Reseach Center Biosignal Reseach Center Tenure-track Assistant Professor Gunma University Initiative for Advanced Research ( GIAR ) 2 0 16
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Institute for Molecular and Cellular RegulationNational University Corporation Gunma University
生体調節研究所 概要国立大学法人 群馬大学
Department of Molecular and Cellular Biology
Department of Molecular Medicine
Biosignal Genome Resource Center
Metabolic Signal Reseach Center
Biosignal Reseach Center
Tenure-track Assistant Professor
Gunma UniversityInitiative for Advanced Research (GIAR) 2016
Our institute was started as the Endocrine Research Facility of Medicine, which was founded in 1951 as an adjunct facility of the Medical Department of Gunma University. At that time, because of insufficient intake of seaweed that caused iodine deficiency, there were many in inland Gunma who suffered from thyroid disease. In 1963, with support from the Science Council of Japan and the Japan Endocrine Society, the Institute of Endocrinology was established as a facility that was directly attached to Gunma University. The institute produced pioneering works such as elucidation of the mechanism of thyroid hormone synthesis, discovery of a new hormonemotilinand generation of antibodies against various hormones. With the progress in molecular and cellular biology, the basic mechanisms of protein sorting, membrane trafficking, and signal transduction were soon revealed, which significantly changed the concept of endocrinology. Furthermore, genetically modified mice that were developed in the 90’s enabled us to directly investigate the in vivo funct ion of specific gene products and their relationship with diseases. In consideration of all these changes, the Inst i tute of Endocr inology was reorganized in 1994 to the Institute for Molecular and Cellular Regulation (IMCR). Since then, our interest has gradually shifted from simple endocrine diseases to
more complex and common diseases such as diabetes, obesity, and atherosclerosis. Neuronal regulation of energy intake and expenditure, and immunological regulation of chronic inflammation have also become our topics of interest as they are involved in metabolic syndromes. We study these diseases via genetically modified mice, nematodes, and yeasts using advanced techniques such as metabolic monitoring, live-cell imaging, epigenetics, and genome editing etc. As such, our mission is to be a unique basic research institute in the field of endocrinology and metabolism in Japan. Our institute has continuously made a mark as a center for the 21st Century Center of Excellence (COE) program from 2002 to 2006, a center for Global COE program in collaboration with Akita University from 2007 to 2011, and as the Joint Usage/Research Center for Endocrine/Metabolism since 2010. Currently, IMCR has been involved in many collaborations to provide domestic and international researchers with unique resources and techniques. IMCR celebrated its 50th anniversary in 2013 and further expanded in 2014 on association with the Gunma University Initiative for Advanced Research. We make continuous efforts to produce high-quality research, despite limited funding, in order to serve the scientific community and general society.
Specific aimse aim to elucidate t e role of stress responses in
carcinogenesis and cellular senescence and to identify diagnostic iomar ers and t erapeutic targets in t ese cellular processes
▶On-going projects variety of N and or protein damaging agents derived from t e environment and cell meta olism activate diverse stress responses inducing genomic insta ility and cellular senescence ic plays a critical role in tumor development and organismal aging respect ively Importantly activated oncogenes also promote genomic insta ility tumor progression and cellular senescence tumor suppression in a parado ical manner t roug t e oncogenic stress response
①Oncogenic stress-induced genomic instability and cellular senescence
ncogene induced a normal N replication and su se uent N damage promote t ese processes t roug poorly understood mec anisms e previously reported t at t e cancer c aperone sp activates
error prone family N polymerases potential ly promoting genomic insta ility in tumor cells ur recent findings suggest t at t ese polymerases participate in t e oncogene induced a errant replication
②Heat Shock Factor (HSF) 1-mediated regulation of cellular senescence
t ranscr ip t iona l l y ac t i va tes ea t oc Response in response to protein damaging stress e recently found t at acute depletion of induces cellular senescence in non stressed cells in a p R dependent manner Interestingly depletion also induces cellular senescence in p )R ) tumor cells ese findings suggest t at regulates senescence t roug redundant pat ays independently of t e eat s oc response
最近の研究成果
Sekimoto T, Oda T, Kurashima K, Hanaoka F, Yamashita T. Both high-fidelity replicative and low-fidelity Y-family polymerases are involved in DNA rereplication. Mol Cell Biol 35:699-715(2015).
Yamashita T, Oda T, Sekimoto T.:Translesion DNA synthesis and hsp90. Genes and Environment 34:89-93(2012)
Pozo FM, Oda T, Sekimoto T, Murakumo Y, Masutani C, Hanaoka F, Yamashita T. Molecular chaperone Hsp90 regulates REV1-mediated mutagenesis. Mol Cell Biol 31:3396-3409(2011)
Sekimoto T, Oda T, Pozo FM, Murakumo Y, Masutani C, Hanaoka F, Yamashita T. The Molecular Chaperone Hsp90 Regulates Accumulation of DNA Polymerase η at Replication Stalling Sites in UV-irradiated Cells Mol Cell 37:79-89(2010)
is process is important for removing from t e lood and maintaining a normal level of Interestingly t e c aracteristics of C elegans yol are uite similar to t ose of mammalian In C elegans yol is secreted from t e intestine and ta en up y oocytes via receptor mediated endocytosis e are studying t e molecular mec anism underlying traffic ing y utili ing t e advanced genetic tec ni ues t at are availa le for C elegans e are also studying t e p ysiological functions of mammalian omologues of t e genes identified y C elegans genetic
studies y generating noc out mice
② nalysis of physiological functions of membrane trafficking during de elopment o elucidate t e p ysiological functions of mem rane traffic ing during development in animals e are utili ing C elegans as a model system for t e study of oogenesis fertili ation and em ryogenesis e ave identified a novel type of developmentally regulated cortical granules in C elegans oocytes e are trying to clarify t e molecular mec anisms underlying t e iogenesis and e ocytosis of t e cortical granules as a model of regulated secretion Recently e also found t at fertili ation induced autop agy is
responsi le for select ive degradat ion of paternal mitoc ondria and t ere y of maternal in eritance of mitoc ondrial N e are no studying t ese p enomena during development in mammals y using a live imaging system of mouse em ryos
③ nalysis of the molecular mechanisms underlying retention of disease-associated membrane proteins e are studying t e molecular mec anisms underlying protein misfolding diseases in ic a normal mem rane proteins accumulate in t e R e are also trying to identify ne t erapeutic targets for suc diseases
最近の研究成果1) Sakaguchi A, Sato M, Sato K, Gengyo-Ando K, Yorimitsu T, Nakai J, Hara T, Sato K, Sato K*. REI-1 is a guanine nucleotide exchange factor regulating RAB-11 localization and function in C. elegans embryos. Dev. Cell 35(2):211-21.(2015)
2) Hara T, Hashimoto Y, Akuzawa T, Hirai R, Kobayashi H, Sato K*. Rer1 and calnexin regulate endoplasmic reticulum retention of a peripheral myelin protein 22 mutant that causes type 1A Charcot-Marie-Tooth disease. Sci Rep. 11;4:6992.(2014)
3) Saegusa K, Sato M, Sato K, Nakajima-Shimada J, Harada A*, Sato K*. C. elegans chaperonin CCT/TRiC is required for actin and tubulin biogenesis and microvillus formation in intestinal epithelial cells. Mol Biol Cell. 15;25(20):3095-104.(2014)
4) Yamasaki A, Hara T, Maejima I, Sato M, Sato K, Sato K*. Rer1p regulates the ER retention of immature rhodopsin and modulates its intracellular trafficking. Sci Rep. 6;4:5973.(2014)
5) Miyuki Sato, Ryosuke Konuma, Katsuya Sato, Kotone Tomura and Ken Sato. Fertilization-induced K63-linked ubiquitination mediates clearance of maternal membrane proteins. Development 141:1324-1331.(2014)
6) Tsukamoto S, Hara T, Yamamoto A, Kito S, Minami N, Kubota T, Sato K, Kokubo T. Fluorescence-based visualization of autophagic activity predicts mouse embryo viability. Sci Rep. 31;4:4533.(2014)
7) Sato M, Sato K.: Maternal inheritance of mitochondrial DNA by diverse mechanisms to eliminate paternal mitochondrial DNA. Biochim Biophys Acta MCR 1833:1979-1984(2013)
8) Sato M, Sato K.: Dynamic regulation of autophagy and endocytosis for cell remodeling during early development. Traffic 14:479-486(2013)
9) Sato M, Sato K.:Degradation of paternal mitochondria by fertilization-triggered autophagy in C. elegans embryos. Science 334:1141-1144(2011)
10) Sato M, Saegusa K, Sato K, Hara T, Harada A, Sato K.: Caenorhabditis elegans SNAP-29 is required for organellar integrity of the endomembrane system and general exocytosis in intestinal epithelial cells. Mol Biol Cell 22:2579-2587(2011)
《目 標》細胞内膜トラフィックは、いわゆるタンパク質の分泌や栄養の吸収等における物質輸送だけではなく動物個体における内分泌・代謝や神経伝達、個体発生のような高次生命機能においても必須の役割を果たしています。私たちの研究室では、線虫 C. elegans やマウスなどのモデル動物を駆使して内分泌代謝や動物の発生などの高次生命現象における細胞内物質輸送の生理的役割とその分子メカニズムの解明を目指しています。また、細胞内物質輸送の異常を起因とする様々な遺伝疾患の発症メカニズムとその治療法の開発を目指しています。
▶現在進行中のプロジェクト① 低密度リポタンパク質(LDL) の細胞内輸送の分子メカニズム 低密度リポタンパク質(LDL)はコレステロールを多く含むため悪玉コレステロールとも呼ばれ、血中量が過剰になると高コレステロール血症や動脈硬化などの原因となります。通常は細胞が血中のLDLを取り込むことで血中量が適切に保たれていますが、この仕組みについては不明な点が多く残されています。実はこのLDLを細胞内に取り込む仕組みは、線虫などのシンプルな動物から哺乳類までよく似ています。線虫 C. elegans の卵に多く含まれる卵黄成分はLDLと非常によく似た性質をしており、卵母細胞によって細胞外から取り込まれ、発生の際の栄養素として蓄えられます。私たちは、この線虫卵による卵黄成分の取り込みの過程に注目し、LDLを細胞内に取り込む際に働く新たな因子の発見および分子メカニズムの解明を目指しています。また、リポタンパク質の分泌の仕組みにも着目し研究を進めています。このように線虫研究で発見された新規因子についてノックアウトマウスを作製し、哺乳動物個体における機能解析も進めています。
② 発生における細胞内物質輸送の新たな生理機能とその分子機構の解明
線虫 C. elegans は雌雄同体で基本的に自家受精によって繁殖するため、一個体の生殖腺内で卵母細胞の成熟、受精、初期発生の過程を継続的に観察できます。私たちは、 C. elegans における表層顆粒を発見し、生きた卵母細胞において表層顆粒の形成、細胞膜との同調的融合などダイナミックに変化する膜動態をリアルタイムで捉えることに成功しています。また、受精後に精子由来のミトコンドリアが自食作用によって分解されることが、ミトコンドリアゲノムの母性遺伝に重要であることも発見しています。現在マウス受精卵を用いた哺乳類の初期発生過程における細胞内膜リモデリングの研究も開始しています。
Specific aimsMem rane traffic ing plays essential roles not only in secretion and nutrient upta e ut also in various p ysiological processes suc as t ose involving t e endocrine system meta olic system and nervous system and t ose occurring during development in animals In our la oratory e study t e molecular mec anisms and p ysiological functions of mem rane traffic ing in multicellular organisms y using t e nematode Caenorhabditis elegans and mice as model systems In addition e study t e molecular mec anisms underlying protein misfolding diseases in ic a normal mem rane proteins accumulate in t e endoplasmic reticulum( R) in order to discover ne targets for t e treatment of suc diseases
▶On-going projects① nalysis of molecular mechanisms underlying
lo -density lipoprotein trafficking in C. elegans o density lipoprotein( ) consists of core proteins and lipids suc as c olesterol In mammals is recogni ed y t e receptor on t e cell surface and is t en ta en up y cells via receptor mediated endocytosis
② インスリンによる糖取り込み促進機構の研究 インスリンは、脂肪細胞、筋細胞などにおいて糖の取り込みを促進し、血糖を降下させる。我々はこのインスリンの糖取り込み促進機構を、グルコーストランスポーター GLUT4の細胞内トラフィッキングという観点から研究している。最近では、GLUT4のリサイクル機構と分解機構に焦点を当て解析している(図4)。
Specific aimslucidation of actions and mec anism of actions
of ormones gro t factors and cyto ines involved i n me ta o l i c r egu l a t i on t i s sue r epa i r and regenerat ion and t e i r p ysiological and pat op ysiological roles in relation to dia etes o esity cancer and tissue fi rosis
▶On-going projects① ction and mechanism of actions of hormones
gro th factors and differentiation factors e are investigating t e actions and mec anism of act ions of var ious ormones gro t factors and d i f fe rent ia t ion factors e are a lso s tudy ing t e p ysiological and pat op ysiological roles of t ese factors in meta olic disorders and tissue fi rosis
( ) ignal transduction pat ays activated y t e s eet taste receptor eet taste receptor e pressed in t e taste ud is a dimer
of R and R It is also e pressed in enteroendocrine cells pancreatic β cells and adipocytes e found t at various agonists for t e s eet taste receptor induce diverse c anges in t e second messengers suc as calcium cyclic M and diacylglycerol e are no investigating t e role of
t e s eet taste receptor in pancreatic β cells and adipocytes
( ) Calcium permea le c annel R e a v e e e n s t ud y i n g t e r e gu l a t i o n o f a calcium permea le cation c annel R e are particularly interested in t e traffic ing of R and p ysiological role of traffic ing of R
② echanism of action of insulin on glucose transport Insulin stimulates glucose transport in adipocytes and muscles y promoting translocation of a glucose transporter G U from t e intracellular storage pool to t e plasma mem rane e ave een studying t e mec anism of insulin regulated G U traffic ing in adipocytes Currently e are studying t e mec anism of insulin induced
do n regulation of G U in adipocytes
最近の研究成果Nagasawa M, Kojima I.: Translocation of TRPV2 channel induced by focal administration of mechanical stress. Physiol Rep 3:e12296(2015)
Hamano K, Nakagawa Y, Ohtsu Y, Li LF, Medina J, Tanaka Y, Masuda K, Komastu M, Kojima I.:(2015) Lactisole inhibits the glucose-sensing receptor in mouse pancreatic β-cells. J Endocrinol 226:57-66(2015)
Kojima I, Nakagawa Y, Hamano K, Medina J, Li LF, Nagasawa M.:(2015) Glucose-sensing receptor T1R3:A new signaling receptor activated by glucose in pancreatic β-cells. Biol Pharm Bull 38:674-679(2015)
Kojima I, Nakagawa Y, Ohtsu Y, Hamano K, Medina J, Nagasawa M.: Return of the glucoreceptor:Glucose activates the glucose-sensing receptor T1R3 and facilitates metabolism in pancreatic β-cellls. J Diab Invest 6: 256-263(2015)
Kubo N, Saito R, Hamano K, Nagasawa M, Aoki F, Takei I, Umezawa K, Kuwano H, Kojima I.:(2014) Conophylline suppresses hepatic stellate cells and attenuates thioacetamide-induced liver fibrosis in rats. Liver Int 43: 1057-1067(2014)
Otsu Y, Nakagawa Y, Nagasawa M, Takeda S, Arakawa H, Kojima I.:(2014) Diverse signaling systems activated by t h e swee t t a s t e - s en s i n g r e c ep t o r i n human GLP-1-secreting cells. Mol Cell Endocrinol 394:70-79 (2014)
Ma J, Nakagawa Y, Kojima I, Shibata H.: Prolonged Insulin Stimulation Downregulates GLUT4 Through Oxidative Stress-Mediated Retromer Inhibition by a Protein Kinase CK2-Dependent Mechanism in 3T3-L1 Adipocytes. J Biol Chem 289:133-142(2014)
Specific aims)Mec anism for regulated e ocytosis of secretory granules e are interested in t e molecular mec anism of secretory granule e ocytosis e are investigating t e functional and mec anical relations ip among doc ing priming and fusion of insulin granules to t e plasma mem rane in living eta cells e pressing multiple fluorescently la eled proteins urt ermore e are studying in vitro and in vivo function of Ra and its effectors e op ilins ic regulate various traffic ing steps of secretory vesicles especially in t e fields of endocrinology meta olism and immunology)Genetic analysis of dia etes and o esity in rodent models e aim to clarify t e genetic alterations t at are responsi le for dia etes and o esity in rodent disease models e are currently investigating t e molecular mec anism of pancreatic eta cell dysfunction and t at of a normal fat accumulation
▶On-going projects)Morp ological analyses of intracellular traffic ing suc as doc ing priming and fusion of secretory granules in living cells y confocal total internal reflection fluorescence and electron microscopes)In vitro and in vivo functional analyses of t e small G ases Ra a and Ra and t eir effectors e op ilins in regulated e ocytosis) ffects of impaired Ra systems on t e pat ogenesis of immune respiratory and s in diseases) Molecular mec anism of adipose fat accumulation in o esity especially focusing on t e role of and its ligand
最近の研究成果Mizuno K, Fujita T, Gomi H, Izumi T.:Granuphilin exclusively mediates functional granule docking to the plasma membrane. Sci ep 6:23909(2016)
Yamaoka M, Ando T, Terabayashi T, Okamoto M, Takei M, Nishioka T, Kaibuchi K, Matsunaga K, Ishizaki R, Izumi T, Niki I, Ishizaki T, Kimura T.:PI3K regulates endocytosis after insulin secretion by mediating signaling crosstalk between Arf6 and Rab27a. ell Sci 129:637-649(2016)
Shimada-Sugawara M, Sakai E, Okamoto K, Fukuda M, Izumi T, Yoshida N, Tsukuba T.:Rab27A regulates transport of cel l surface receptors modulat ing multinucleation and lysosome-related organelles in osteoclasts. Sci ep 5:9620(2015)
Zasłona Z, Okunishi K, Bourdonnay E, Domingo-Gonzalez R, Moore BB, Lukacs NW, Aronoff DM, Peters-Golden M.: Prostaglandin E₂ suppresses allergic sensitization and lung inflammation by targeting the E prostanoid 2 receptor on T cells. llergy lin mmunol 133:379-387(2014)
Okunishi K, DeGraaf AJ, Zasłona Z, Peters-Golden M.:Inhibition of protein translation as a novel mechanism for prostaglandin E2 regulation of cell functions. F S 28: 56-66(2014)
▶現在進行中のプロジェクト① 膵β細胞におけるインスリン顆粒開口放出機構 インスリン顆粒を蛍光標識し、生きた膵β細胞でリアルタイムに開口放出現象を可視化すると、膜融合直前の顆粒の細胞内動態は一様ではなく、細胞膜からの距離や細胞膜近傍での停留時間がさまざまな顆粒からの開口放出が認められる( a 2008; 図1)。私たちは、インスリン顆粒膜に局在するGranuphilinを発見し、本分子が単量体GTPase Rab27aまたはRab27bのエフェクターとして、インスリン顆粒の細胞膜ドッキングに必須であるのみならず、次の膜融合反応を抑制することを見出した( l C e 1999, 2004, 2011; l Cell l 2002a;
Cell l 2005; 図2)。最近、Granuphilinによる膜融合反応の抑制が不可逆的な変化ではないことや、Granuphilinを含むドッキング装置のナノ構造を明らかにした( e 2016)。また、Granuphilinとは別のRab27エフェクター分子、Exophilin8が、刺激依存性に細胞内部から細胞膜近傍へ分泌顆粒を供給すること( l l Cell 2011)、Exophilin7が、細胞膜にドッキングしていない分泌顆粒の開口放出に関与することを見出した( l l Cell 2013)。さらに、分泌顆粒の生成と開口放出を連関すると考えられる、別のRab27エフェクターの役割を解析している。現在、これら分子や関連分子を多色蛍光により標識し、全反射顕微鏡で観察することによって、分泌顆粒の開口放出分子機構を、生細胞で動的に解析している。
② 高分化分泌細胞におけるRab27a/bおよびそのエフェクターExophilinsの役割
私たちは、Rab27a/bおよびそのエフェクター Exophilinsファミリー分子が、多様な分泌細胞に発現し、分泌小胞の開口放出を調節していることを見出している( e 2002; l Cell l 2002b; l
l Cell 2007a)。実際、Rab27aおよびGranuphilinは、栄養素によるインスリン分泌シグナルの作用点であること( Cl n n es 2005; Cell e a 2006)、Exophilin4は、グルコース刺激に対して膵β細胞とは全く逆の分泌反応を示す膵α細胞でグルカゴン顆粒の細胞膜ドッキングに関与すること( l l Cell 2007b)、X染色体上にあるGranuphilin遺伝子は、視床下部において著明な発現の性差を示し、性特異的な行動を制御していること(Cell 2012)、などがわかった。現在、Rab27a/bやそのエフェクターの遺伝子変異マウスを用いて、調節性分泌機構の異常が、多様な細胞が相互に作用する免疫アレルギー系、呼吸器、皮膚などにおいて、その生理機構や疾患病態に及ぼす影響を調べている(図3)。
③ 病態モデル動物を用いた、糖尿病・肥満の成因や病態生理 私たちは、常染色体優性遺伝様式を示す糖尿病モデルAkitaマウスでは、インスリン2A鎖第7番目システイン残基がチロシン残基へ置換され、A7-B7間の分子内ジスルフィド結合が形成されず、インスリンが分泌されなくなることを発見している( Cl n n es , 1999; a e es 2003)。この知見は、小胞体品質管理機構や小胞体ストレスの膵β細胞機能における重要性を報告した最初のもので、同様のインスリン遺伝子異常がヒト新生児糖尿病の原因となるという発見の先駆けとなった。また、多因子遺伝性糖尿病・肥満マウスの遺伝学的解析を行い、その血糖値・体重・インスリン値などを制御する遺伝子の染色体上局在部位を特定し( a e es 1999; a en e 2006)、第2染色体上にあるTGFβ type I 受容体の1つであるALK7の遺伝子変異を同定した。本分子は、Smad2-4を介して脂肪細胞の転写因子C/EBPαとPPARγを抑制することによって、過栄養状態において脂肪分解を抑制して脂質を脂肪細胞に蓄積する機能を有することを発見した( a e es 2013;
e 2013; 図4)。ALK7の機能を抑制すれば、脂肪細胞を小型化することによって、肥満に伴う代謝異常や慢性炎症を軽減できること
② 生活習慣病における亜鉛シグナルの役割解明 亜鉛トランスポーターを介して細胞内外に転送される亜鉛イオンは、様々な細胞機能を調節するシグナルとして機能することが明らかになってきた。我々はこれまでに、ZnT8に依存して膵β細胞からインスリンとともに分泌される亜鉛が、肝臓においてインスリン分解を制御することを明らかにした(Tamaki et al. JCI 2013)。亜鉛トランスポーターを切り口に、生活習慣病における亜鉛シグナルの役割解明に挑みたい(図2)。
③ 生活習慣病におけるオートファジーの機能解析 膵β細胞でオートファジー誘導に必須の遺伝子Atg7を欠損するマウスは、ブドウ糖応答性インスリン分泌の低下や、高脂肪食負荷時におけるβ細胞量の代償性増加不全など糖尿病に特徴的な表現型を示す(Ebato et al. Cell Metab 2008)。諸臓器におけるオートファジーの機能不全が全身での糖代謝の異常を引き起こす可能性がある。オートファジーの視点から生活習慣病の病態解明に挑みたい(図3)。
④ 小腸上皮細胞の機能制御を司る分子の探索ならびに機能解析 Rab8のノックアウトマウスは離乳期に当たる限られた時期に栄養吸収不全で死亡するという興味深い表現型が観察された(Sato T et al. Nature 2007)。本研究では、離乳に伴い劇的に変化する小腸上皮組織の機能成熟課程において、膜輸送をはじめとする様々な細胞機能がどのように制御されているかに焦点をあて、その過程における未知のシグナル伝達系やエピゲノム制御メカニズムの探索を行なう(図4)。
Our researche dysfunction of pancreatic β cells ro n adipocytes and
enterocytes can cause dia etes and meta olic syndrome ur goal is to elucidate t e molecular mec anism involved in
t e maintenance of omeostasis of t ese ig er order function cells ic is t e ey to glucose meta olism e aim to elucidate t e mec anism of cellular omeostasis from a variety of vie points including developmental iology inc iology autop agy and cell polarity y effectively utili ing
genetically engineered mice urt ermore using our findings from asic medical researc e aim to esta lis a ground rea ing treatment for dia etes and o esity
▶On-going projects①Research on the de elopmental iology of pancreatic cells② unctional analysis of autophagy in lifestyle associated diseases③Analysis of zinc transporters in ol ed in the rowning of adipocytes④Screening and functional analysis of molecules in ol ed in the
regulation of enterocytes
主要論文) Shigihara N et al lin n est ( )) Sato T et al ell Sci ( )) Tamaki M et al lin n est ( )) ato et al ell Meta ( )) Sato T et al Nature ( )
最近の研究成果Watada H, Fujitani Y. Minireview: Autophagy in pancreatic β-cells and its implication in diabetes. ol ndocrinol 29:338-348(2015)
Sasaki S, Miyatsuka T, Matsuoka TA, Takahara M, Yamamoto Y, Yasuda T, Kaneto H, Fujitani Y, German MS, Akiyama H, Watada H, Shimomura I. Activation of GLP-1 and gastrin signalling induces in vivo reprogramming of pancreatic exocrine cells into beta cells in mice.
iabetologia 58:2582-2591(2015)
Shigihara N, Fukunaka A, Hara A, Komiya K, Honda A, Uchida T, Abe H, Toyofuku Y, Tamaki M, Ogihara T, Miyatsuka T, Hiddinga HJ, Sakagashira S, Koike M, Uchiyama Y, Yoshimori T, Eberhardt NL, Fujitani Y, Watada H. Human IAPP-induced pancreatic beta cell toxicity and its regulation by autophagy. lin n est 124:3634-3644(2014)
Yamamoto E, Uchida T, Abe H, Taka H, Fujimura T, Komiya K, Hara A, Ogihara T, Fujitani Y, Ueno T, Takeda S, Watada H. Increased expression of ERp57/GRP58 is protective against pancreatic beta cell death caused by autophagic failure. iochem iophys es ommun 453: 19-24(2014)
Sato T, Iwano T, Kunii M, Matsuda S, Mizuguchi R, Jung Y, Hagiwara H, Yoshihara Y, Yuzaki M, Harada R, Harada A. Rab8a and Rab8b are essential for several apical transport pathways but insufficient for ciliogenesis. ell Sci 127:422-431(2014)
Guo L, Inada A, Aguayo-Mazzucato C, Hollister-Lock J, Fujitani Y, Weir GC, Wright CV, Sharma A, Bonner-Weir S. PDX1 in ducts is not required for postnatal formation of β-cells but is necessary for their subsequent maturation. iabetes 62:3459-3468(2013)
Tamaki M, Fujitani Y, Hara A, Uchida T, Tamura Y, Takeno K, Kawaguchi M, Watanabe T, Ogihara T, Fukunaka A, Shimizu T, Mita T, Kanazawa A, Imaizumi MO, Abe T, Kiyonari H, Hojyo S, Fukada T, Kawauchi T, Nagamatsu S, Hirano T, Kawamori R, Watada H. The diabetes-susceptible gene SLC30A8/ZnT8 regulates hepatic insulin clearance. lin n est 123:4513-4524(2013)
Ishibashi K, Hara A, Fujitani Y, Uchida T, Komiya K, Tamaki M, Abe H, Ogihara T, Kanazawa A, Kawamori R, Watada H. Beneficial effects of vildagliptin combined with miglitol on glucose tolerance and islet morphology in diet-controlled db/db mice. iochem iophys es
ommun 440:570-575(2013)
Abe H, Uchida T, Hara A, Mizukami H, Komiya K, Koike M, Shigihara N, Toyofuku Y, Ogihara T, Uchiyama Y, Yagihashi S, Fujitani Y, Watada H. Exendin-4 improves β-cell function in autophagy-deficient β-cells. ndocrinology 154:4512-4524(2013)
Ohara-Imaizumi M, Kim H, Yoshida M, Fujiwara T, Aoyagi K, Toyofuku Y, Nakamichi Y, Nishiwaki C, Okamura T, Uchida T, Fujitani Y, Akagawa K, Kakei M, Watada H, German MS, Nagamatsu S. Serotonin regulates glucose-stimulated insulin secretion from pancreatic β cells during pregnancy. roc atl cad Sci S 110:19420-19425(2013)
Laboratory of e elo ental iolo y an Metabolis
23
病態制御部門
脳病態制御分野研究スタッフ Staff
ProfessorAkiko HAYASH TAKAGAssociate ProfessorKoichi SATOAssistant Professor
hihiro MOGResearch ellowTakeyoshi ADAResearch ellowTsuyoshi H YAMAResearch ellowAyaka TO OAssistant TechnicianMutsumi TAKANOAssistant TechnicianMayumi NAKAM RAAssistant Technician
mi HOSOYAGraduate Student (D
ukutoshi SH RAMD PhD ourse StudentTakayuki MAMD PhD ourse StudentMari M A A
② シナプス光遺伝学などの最先端イメージング技術を用いた精神疾患モデルマウスにおける疾患関連神経回路の可視化
我々の強みであるin vivo 2光子励起顕微鏡による生体脳シナプスイメージングは非常に有力な方法ですが、シナプスと行動の相関は模索出来ても、因果関係まで踏み込むのは困難です。そこで長期増強したシナプス後部を特異的に標識・退縮させる新規光感受性シナプスプローブ(ASプローブ)の開発を行っています(図2)。ASプローブによるシナプスマッピングを行い関連回路を可視化すること、さらにマッピングされたシナプスを光刺激特異的に書き換えることで、高次脳機能とシナプスとの関連について因果律に迫れる研究に挑戦しています(Hayashi-Takagi A et al, Nature, 2015)。
③ 細胞外pHを感知する新しいGタンパク質共役型受容体(GPCR)の機能解析 OGR1ファミリーは、細胞外の生理的な範囲のプロトン(pH 6-8)を感知するGPCRであり、神経細胞を含めた様々な細胞に発現しています。細胞外プロトンはpH 7.4でも40 nM存在し、腫瘍・虚血や炎症部位では1000 nM (pH 6.0)にも増加します。OGR1ファミリー GPCRの生理機能と病態との関連について、中枢神経系、骨代謝、炎症性疾患を中心にノックアウトマウスを用いた研究や、新規に開発されたGPCRアンタゴニストを用いて解析しています(図3)。
Specific aimsrug discovery in neuropsyc iatry as een limited to
c emical modifications of compounds originally discovered serendipitously erefore more mec anism oriented strategies of drug discovery for neuropsyc iatric disorders are a aited e deterioration of t e neuronal circuit as attracted attention as t e pat op ysiology of t ese disorders and a errant responses against t e stress suc as o idative stress is no eing considered as a possi le causal signaling in t ese diseases us e a im to e lucidate t e disease relevant signaling pat ay y utili ing state of art imaging tec ni ue eventually c allenging to identify a novel t erapeutic target for neuropsyc iatric disorders
▶On-going projects( ) amination of neuronal stress response for t e drug discovery
of neuropsyc iatric disorders ig ) e are performing t e ig t roug put in vitro screening system as ell as in vivo p oton rain imaging of disease model so t at uantitative measurement
of t e synaptic deterioration and stress related meta olites are no eing investigated oget er it e avioral assessment e aim to identify a novel t erapeutic target for neuropsyc iatric
disorders
( ) isuali ation of t e disease relevant neurocircuits in t e neuropsyc iatric model mice us far t e lin s et een synapses and rain functions ave een largely correlational ecause of lac s of a tec ni ue for manipulating individual
synapse erefore e are engineering a novel synaptic optopro e aRac to c allenge t e causal relations ip et een synapse and ig er rain functions aRac
specifically visuali es t e recently ritten synapse and ritten trace can e erased y lue lig t ig ayas i a agi et al Nature is novel lig t dependent tool of ynaptic optogenetics s ould open up ne areas of rain researc and y e tension s ed lig t on t e neural net or s t at determine o e are
( ) ysiological and pat op ysiological roles of proton sensing G CRs e ave recently found t at GR family a group of G CRs sense e tracellular p tracellular protons are appro imately nM p under p ysiological conditions
ile it reac nM p in tumor isc emia and inflammation s suc t e monitoring t e e tracellular p y t e GR family mem ers triggers t e diverse do nstream
signaling ic ro ustly regulates cellular manifestations y utili ing t e gene engineering tec ni ues and p armacological intervention it novel G CR antagonists e c allenge to elucidate t e role of GR family in p ysiological and pat op ysiological conditions ig
最近の研究成果(下線、現および旧所属者)(1)Hayashi-Takagi A, Yagishita S, Nakamura M, Shirai F, Wu YI, Loshbaugh AL, Kuhlman B, Hahn KM, Kasai H. Labelling and optical erasure of synaptic memory traces in the motor cortex.(2015) ature 525(7569):333-8
(2)Hayashi-Takagi A, Araki Y, Nakamura M, Vollrath B, Duron SG, Yan Z, Kasai H, Huganir RL, Campbell DA, Sawa A. PAKs inhibitors ameliorate schizophrenia-associated dendritic spine deterioration in vitro and in vivo during late adolescence.(2014) roc atl cad Sci S 111(17):6461-6
(3)Jin Y, Sato K, Tobo A, Mogi C, Tobo M, Murata N, Ishii S, Im DS, Okajima F. Inhibition of interleukin-1β production by extracellular acidification through the TDAG8/cAMP pathway in mouse microglia. (2014) eurochem 129:683-695
(4)Hayashi-Takagi A, Takaki M, Graziane N, Seshadri S, Murdoch H, Dunlop AJ, Makino Y, Seshadri AJ, Ishizuka K, Srivastava DP, Xie Z, Baraban JM, Houslay MD, Tomoda T, Brandon NJ, Kamiya A, Yan Z, Penzes P, Sawa A. Disrupted-in-Schizophrenia 1 (DISC1) regulates spines of the glutamate synapse via Rac1.(2010) at eurosci 13(3):327-32
(5)Mogi C, Tobo M, Tomura H, Murata N, He XD, Sato K, Kimura T, Ishizuka T, Sasaki T, Sato T, Kihara Y, Ishii S, Harada A, Okajima F. Involvement of proton-sensing TDAG8 in extracel lular acidification-induced inhibition of proinflammatory cytokine production in peritoneal macrophages.(2009) mmunol 182(5):3243-51
最近、CRISPR/Casという効率がよく簡便なゲノム編集システムが開発されました(図2)。このシステムではガイドRNAというゲノム中の標的と相補的な短いRNAとCas9というDNA切断酵素の複合体が標的を切断することにより高効率にノックアウト細胞を作製することができます。当教室では、このシステムの改良をおこなうとともに、このシステムを用いてエピジェネティクス関連遺伝子が関与する疾患モデルを作製し、研究をおこなっています。方法には2通りあり、その1つはCRISPR/Casゲノム編集で疾患モデル動物を作製する方法です(Horii et al. 2014)。またヒト細胞における表現型を調べたいときはiPS細胞の遺伝子を改変することにより疾患モデルiPS細胞を作製して研究に用いています(Horii et al. 2013)。このようにして作製した疾患モデルiPS細胞は患者から作製したものと異なり、作製の元になった正常人由来のiPS細胞をコントロールとして研究にもちいれば遺伝的背景の違いによる表現型の違いがないので非常に有用です。
③ エピゲノム編集への応用 現在、特定の遺伝子のメチル化などの遺伝子のスイッチを自在に制御する方法はありません。そのため、特定のメチル化が本当に疾患を発症しているかを本当に証明することはできませんし、また特定の遺伝子のメチル化を変化させることで治療をおこなうこともできません。そこでDNA切断活性のないCRISPR/Casが特定の配列に結合することを利用して遺伝子のメチル化を自在に制御する技術を開発して、このような用途に利用できるようにしようと試みています。
Specific aimes (Fig 1)pigenetics or s as a gene s itc ic is affected y life
style e aims to clarify o life style affects t is gene s itc and cause diseases mec anisms of gene s itc es evelopment of epigenome editing for epigenetic t erapy
▶On-going projectsi eno e an iseases
It as een long time after starting e tensive genetic analysis of uman diseases o ever some of t e diseases are found not to e caused y genetic c anges rat er y t e alteration of
epigenome ic is t e s itc of t e genes errant c anges of epigenome caused y life style results in several diseases li e dia etes It as also found t at mutations of genes involved in t e gene s itc also cause t ese diseases erefore e study
noc out mice of t ese genes to analy e t e effect of anomaly of t e s itc es
mpro ement of S as genome editing technologyRecently a ne tec nology called CRI R Cas for efficient genome editing system as een developed ( ig ) In t is system an endonuclease called Cas cleaves t e target site it a s ort RN (guide RN )complementary to t e target noc out mice can e efficiently made y using t is system e are improving t is tec nology and also use it for ma ing disease model ere are t o ays for t is purpose ne ay is to ust ma e noc out mouse it t is tec nology nd t e ot er is to ma e i model from normal i cells is i model is useful for disease researc ecause it can e clude t e genetic variances
e elopment o f epigenome edi t ing using S as
ere is no efficient met od for regulating N met ylation of specific genes erefore it is impossi le to demonstrate t e role of specific met ylation in diseases and t ere is no epigenome t erapy for a specific gene e are developing t e epigenome editing using Cas deficient for nuclease activity
最近の研究成果Rumbajan JM, Yamaguchi Y, Nakabayashi K, Higashimoto K, Yastuki H, Nishioka K, Matsuoka K, Aoki S, Toda S, Takeda S, Seki H, Hatada I, Hata K, Soejima H, Joh K.The HUS1B promoter is hypomethylated in the placentas of low-birth-weight infants.
ene, 583:141-16(2016).
Hirano H, Gootenberg JS, Horii T, Abudayyeh OO, Kimura M, Hsu PD, Nakane T, Ishitani R, Hatada I, Zhang F, Nishimasu H, Nureki O. Structure and Engineering of Francisella novicida Cas9. ell, 164:950-961(2016)
Morita S, Nakabayashi K, Kawai T, Hayashi K, Horii T, Kimura M, Kamei Y, Ogawa Y, Hata K, Hatada I. Gene expression profiling of white adipose tissue reveals paternal transmission of proneness to obesity. Scientific eports, 6:21693(2016)
Kafer GR, Li X, Horii T, Suetake I, Tajima S, Hatada I, Carlton PM. 5- Hydroxymethylcytosine Marks Sites of DNA Damage and Promotes Genome Stability.
ell ep., 14:1283-1292(2016)
Hattori M, Yokoyama Y, Hattori T, Motegi SI, Amano H, Hatada I, Ishikawa O. Global DNA hypomethylation and hypoxia-induced expression of the ten eleven translocation (TET) family, TET1, in scleroderma fibroblasts. p ermatol , 24:841-846(2015)
Horii T, Yamamoto M, Morita S, Kimura M, Nagao Y, Hatada I. p53 Suppresses Tetraploid Development in Mice. Scientific eports, 5:8907(2015)
Ehara T, Kamei Y, Yuan X, Takahashi M, Kanai S, Tamura E, Tsujimoto K, Tamiya T, Nakagawa Y, Shimano H, Takai-Igarashi T, Hatada I, Suganami T, Hashimoto K, Ogawa Y. Ligand-Activated PPARα-Dependent DNA Demethylation Regulates the FattyAcid β-Oxidation Genes in the Postnatal Liver. iabetes, 64:775-784(2015)
Horii T, Arai Y, Yamazai M, Morita S, Kimura M, Itoh M, Abe Y, Hatada I.: Validation of microinjection methods for generating knockout mice by CRISPR/Cas-mediated genome engineering. Sci ep 4: 4513(2014)
Morita S, Horii T, Kimura M, Arai Y, Kamai Y, Ogawa Y, Hatada I.: Paternal Allele Influences High Fat Diet-Induced Obesity. oS One 9: e85477(2014)
Specific aimese aim at clarifying t e follo ing topics t roug t e use of
genetically engineered animal models( ) Mec anisms for meta olic regulation at t e molecular
level( ) Regulation of meta olism related genes y meta olic
signals suc as ormones autonomic nervous systems and nutrients
▶On-going projects① e are trying to elucidate t e molecular mec anism for
pancreatic βeta cell dysfunction in type dia etes y analy ing pancreas specific genetically manipulated animals ig
② e are trying to clarify o meta olic signals regulate energy omeostasis in t e ypot alamus at t e molecular level ig
and
③ e are also investigating t e molecular mec anism y ic plasma glucagon level is increased in type dia etes
④ e are searc ing for novel target genes and novel interacting proteins for o and irt y mass spectrometry
⑤ e are developing a ne glucagon sand ic I system and y using t is met od e are also re evaluating plasma glucagon
levels in various conditions
⑥ e are also investigating molecular mec anism for t e e tra eneficial effects of anti dia etes drugs to ard controlling ody eig t and glucagon secretion
e elieve t at t ese studies ill lead to ne strategies to treat or prevent meta olic syndrome
最近の研究成果Ghanem S, Heinrich G, Lester S, Pfeiffer V, Bhattacharya S, Patel P, DeAngelis A, Dai T, Ramakrishnan S, Smiley Z, Jung D, Lee Y, Kitamura T, Ergun S, Kulkarni R, Kim J, Giovannucci D, Najjar S. Increased glucose-induced secretion of glucagon-like peptide-1 in mice lacking the carcino-embryonic antigen-related cell adhesion molecule 2. iol hem 291:980-988(2016)
Sasaki T, Kinoshita Y, Matsui S, Kakuta S, Yokota-Hashimoto H, Kinoshita K, Iwasaki Y, Kinoshita T, Yada T, Amano N, Kitamura T. N-methyl D-aspartate receptor co-agonist D-serine suppresses intake of high-preference food. m hysiol egul ntegr omp hysiol 309:R561-575(2015)
Sasaki T, Kuroko M, Sekine S, Matsui S, Kikuchi O, Susanti VY, Kobayashi M, Tanaka Y, Yuasa T, Kitamura T. Overexpression of insulin receptor partially improves obese and diabetic phenotype in db/db mice. ndcr 62:787-796(2015)
Sasaki T, Hiraga H, Yokota-Hashimoto H, Kitamura T. Miglitol protects against age-dependent weight gain in mice: A potential role of increased UCP1 content in brown adipose tissue. ndcr 62:469-473(2015)
Cook JR, Matsumoto M, Banks AS, Kitamura T, Tsuchiya K, Accili D. A mutant allele encoding DNA-binding-deficient Foxo1 differentially regulates hepatic glucose and lipid metabolism. iabetes 64:1951-1965(2015)
Kohno D, Lee S, Harper MJ, Kim KW, Sone H, Sasaki T, Kitamura T, Fan G, Elmquist JK. Dnmt3a in Sim1 neurons is necessary for normal energy homeostasis. eurosci 34:15288-15296(2014)
Yoshino S, Satoh T, Yamada M, Hashimoto K, Tomaru T, Katano-Toki A, Kakizaki S, Okada S, Shimizu H, Ozawa A, Tuchiya T, Ikota H, Nakazato Y, Mori M, Matozaki T, Sasaki T, Kitamura T, Mori M. Protection against high-fat diet-induced obesity in Helz2-deficient male mice due to enhanced expression of hepatic leptin receptor. ndocrinology 155:3459-3472(2014)
Takamoto I, Kubota N, Nakaya K, Kumagai K, Hashimoto S, Kubota T, Inoue M, Kajiwara E, Katsuyama H, Obata A, Sakurai Y, Iwamoto M, Kitamura T, Ueki K and Kadowaki T. TCF7L2 in pancreatic beta cells plays crucial roles in glucose homeostasis by regulating beta-cell mass.
iabetologia 57:542-553(2014)
Susanti V-Y, Sasaki T, Yokota-Hashimoto H, Matsui S, Lee Y-S, Kikuchi O, Shimpuku M, Kim H-J, Kobayashi M and Kitamura T. Sirt1 reverses the obesity by insulin-resistant constitutively-nuclear FoxO1 in POMC neurons of male mice. Obesity 10:2115-2119(2014)
Sasaki T, Kikuchi O, Shimpuku M, Susanti V-Y, Yokota-Hashimoto H, Taguchi R, Shibusawa N, Sato T, Tang L, Amano K, Kitazumi T, Kuroko M, Fujita Y, Maruyama J, Lee Y-S, Kobayashi M, Nakagawa T, Minokoshi Y, Harada A, Yamada M ,Kitamura T.: Hypothalamic Sirt1 prevents age-associated weight gain by improving leptin sensitivity in mice. iabetologia 57:819-831(2014)
Lee Y-S, Kobayashi M, Kikuchi O, Sasaki T, Kim H-J, Yokota-Hashimoto H, Susanti V-Y, Ido-Kitamura Y, Kitamura T.: ATF3 expression is induced by low glucose in pancreatic alpha and beta cells and regulates glucagon but not insulin gene transcription. ndocr 61:85-90(2014)
Kitamura T.: The role of FOXO1 in b-cell failure and type 2 diabetes mellitus. at e ndocrinol 9:615-623(2013)
Sasaki T, Shimpuku M, Kitazumi T, Hiraga H, Nakagawa Y, Shibata H, Okamatsu-Ogura Y, Kikuchi O, Kim HJ, Fujita Y, Maruyama J, Susanti VY, Yokota-Hashimoto H, Kobayashi M, Saito M, Kitamura T.: Miglitol prevents diet-induced obesity by stimulating brown adipose tissue and energy expenditure independent of preventing the digestion of carbohydrates. ndocr 60: 1117-1129(2013)
Lee Y-S, Sasaki T, Kobayashi M, Kikuchi O, Kim H-J, Yokota-Hashimoto H, Shimpuku M, Susanti V-Y, Ido-Kitamura Y, Kimura K, Inoue H, Tanaka-Okamoto M, Ishizaki H, Miyoshi J, Ohya S, Tanaka Y, Kitajima S, Kitamura T.: Hypothalamic ATF3 is involved in regulating glucose and energy metabolism. iabetologia 56:1383-1393(2013)
Kitamura YI, Sasaki T, Kobayashi M, Kim H-J, Lee Y-S, Kikuchi O, Yokota-Hashimoto H, Iizuka K, Accili D, Kitamura T.: Hepatic FoxO1 Integrates Glucose Utilization and Lipid Synthesis Through Regulation of Chrebp O-glycosylation. oS One 7:e47231 (2012)
Talchai C, Xuan S, Kitamura T, Depinho RA, Accili D.: Generation of functional insulin-producing cells in the gut by Foxo1 ablation. ature enet 44:406-412(2012)
Kikuchi O, Kobayashi M, Amano K, Sasaki T, Kitazumi T, Kim HJ, Lee YS, Yokota-Hashimoto H, Kitamura YI, Kitamura T.: FoxO1 Gain of Function in the Pancreas Causes Glucose Intolerance, Polycystic Pancreas, and Islet Hypervascularization. oS One 7:e32249(2012)
Kobayashi M, Kikuchi O, Sasaki T, Kim HJ, Yokota-Hashimoto H, Lee YS, Amano K, Kitazumi T, Susanti VY, Kitamura YI, Kitamura T.: FoxO1 as a Double-edged Sword in the Pancreas: Analysis of Pancreas and β Cell-specific FoxO1 Knockout Mice. m hysiol - ndocrinol etab 302: E603-613(2012)
Kim HJ, Kobayashi M, Sasaki T, Kikuchi O, Amano K, Kitazumi T, Lee YS, Yokota-Hashimoto H, Susanti VY, Ido-Kitamura Y, Nakae J, Kitamura T.: Over-expression of FoxO1 in the Hypothalamus and Pancreas Causes Obesity and Glucose Intolerance. ndocrinology 153:659-671(2012)
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生体情報シグナル研究センター
分泌制御分野StaffAssociate ProfessorSei i ToriiResearch ellow
hisato Ku otaGraduate StudentRyosuke ShintokuAssociate ProfessorNo ukazu NamekiAssociate ProfessorKeiichi YamadaAssociate ProfessorHiroaki HoriuchiAssociate ProfessorToshitada Yoshiharaoint Research ellow
② 膵β細胞、神経細胞の生存増殖と細胞死シグナルの研究 グルコース(高血糖)は膵β細胞からのインスリン分泌を促すだけでなく、細胞増殖を誘導することが知られ、この連関機構の解明は糖尿病の病態を理解するために重要である。分泌顆粒蛋白質フォグリンは、分泌されたインスリンによるオートクライン作用を制御することでβ細胞の増殖に関与している(図3)。現在、糖尿病の病態との関連を調べている。 私たちは以前、低血糖持続が引き起こす膵β細胞の細胞死は、活性酸素種や脱リン酸化酵素MKP1などが関わる複合型の細胞死であることを明らかにした。また虚血性の神経細胞死に、ミトコンドリアに加えてリリソソーム由来の活性酸素種が関与することを見出した。さまざまな病態に関わると予想される新規細胞死フェロトーシスの機構解明にも取り組んでいる(図4)。
③ 低分子化合物を利用した細胞機能および疾患病態の解析 連携する理工学部において新しく開発された発光プローブを使用し、生体情報を可視化するイメージング研究を行っている。また共同研究者が開発した新規低分子化合物について、抗腫瘍活性測定などを行っている。
Specific aimso elucidate formation mec anisms for ig ly
integrated functions of differentiated cells suc as pancreatic β cells and neuronal cells it use of molecular and cellular tec nical approac es
▶On-going projects① echanisms on peptide hormones secretion and
secretory granule formation in endocrine cells eptide ormones synt esi ed at t e endoplasmic reticulum are transported to t e trans Golgi net or GN ere t ey are sorted and specifically targeted to secretory granules in neuroendocrine cells e found t at secretory granule protein p ogrin inds to
C and clat rin adaptors t roug t e luminal region and t e cytoplasmic tail respectively suggesting t at t is transmem rane protein as a role in ormone sorting y providing a communication device et een t e granule lumen and t e cytosol e furt er investigate t e regulatory secretion and degradation of peptide ormones using a recently developed multi tag imaging system
② echanisms on gro th sur i al and cell death in pancreatic -cells and neuronal cells
e ave discovered t at p ogrin functions as a regulatory mediator ridging et een glucose insulin secretion and autocrine insulin signaling in t e gro t of pancreatic β cells e are analy ing its p ysiological role it use of t e gene targeted mouse In addition e investigate t e signaling pat ay of novel necrotic cell deat suc as necroptosis and ferroptosis it tumor cells or neuronal cells
③ e elopment of fluorescent probes or anti-tumor compounds for in estigating arious diseases
In a colla orative study it some engineering groups e are developing fluorescent or luminescent pro es to dissect molecular mec anisms of dysfunction in cancer dia etes and ot er diseases e demonstrated previously t at reactive o ygen species are locali ed at autop agosomes lysosomes in a asal state and t ey are eventually implicated to neuronal cell deat y cere ral isc emia
最近の研究成果Aoyagi K, Ohara-Imaizumi M, Itakura M, Torii S, Akimoto Y, Nishiwaki C, Nakamichi Y, Kishimoto T, Kawakami H, Harada A, Takahashi M, Nagamatsu S.: VAMP7 regulates autophagy to maintain mitochondrial homeostasis and to control insulin secretion in pancreatic β-cells. iabetes 65:1648-1659(2016)
Torii S, Shintoku R, Kubota C, Yaegashi M, Torii R, Sasaki M, Suzuki T, Mori M, Yoshimoto Y, Takeuchi T. Yamada K.: An essential role for functional lysosomes in ferroptosis of cancer cells. iochem 473:769-777(2016)
Gomi H, Morikawa S, Shinmura N, Moki H, Yasui T, Tsukise A, Torii S, Watanabe T, Maeda Y, Hosaka M.: Expression of secretogranin III in chicken endocrine cells: Its relevance to the secretory granule properties of peptide prohormone processing and bioactive amine contents. Histochem
ytochem 63:350-366(2015)
Sun M, Watanabe T, Bochimoto H, Sakai Y, Torii S, Takeuchi T, Hosaka M.: Multiple sorting systems for secretory granules ensure the regulated secretion of peptide hormones. raffic 14:205-218(2013)
Gomi H, Kubota-Murata C, Yasui T, Tsukise A, Torii S.: Immunohistochemical analysis of IA-2 family of protein tyrosine phosphatases in rat gastrointestinal endocrine cells. Histochem ytochem 61:156-168(2013)
Hou N, Mogami H, Kubota-Murata C, Sun M, Takeuchi T, Torii S.: Preferential release of newly synthesized insulin assessed by a multi-label reporter system using pancreatic β-cell line MIN6. oS One 7:e47921(2012)
Specific aimsu a r y o t i c c e l l s a r e c ompo s e d o f ma n y
mem rane ound o rgane l l es、and s apes compositions and functions of t ese organelles are dynamically regulated under various situations Mem rane traffic ing mediates transport et een t em and determines t e identity of eac organelle
ic ases organellar dynamics e aim of our researc is to understand t e molecular mec anisms and p ysiological roles of mem rane traffic ing during animal development
▶On-going projects① utophagy of paternal mitochondria in C. elegans
embryos uring t e development of multicellular organisms eac cell c anges its nature t roug t e remodeling of cellular constituents In particular fertili ation as t e start of a ne life triggers dramatic cellular remodeling called t e oocyte to ygote em ryo transition Using C elegans as a model system e ave s o n t at lysosomal pat ays are transiently activated in t is period and promote selective turnover of maternally and paternally in erited proteins and organelles ig Upon fertili ation autop agy is locally induced around penetrating sperm and selectively degrades paternal mitoc ondria and M s sperm specific organelles ig )
is autop agic degradation of t e paternal mitoc ondria also e plains y mitoc ondrial N is maternally in erited e are trying to elucidate o paternal organelles are recogni ed and selectively engulfed y autop agosomes e are also interested in t e p ysiological and evolutional significance of t is autop agic degradation of paternal organelles
② ndocytic degradation of maternal membrane proteins in C. elegans embryos
In addition to autop agy endocytosis is also upregulated after fertili ation and do nregulates maternal mem rane proteins t roug t e multivesicular ody M ) pat ay ig e found t at lin ed u i uitination of t e su strates is involved in t ese processes ig e are trying to elucidate molecular mec anisms of t is selective endocytosis and t e signaling pat ay t at induces u i uitination after fertili ation
最近の研究成果Aisa Sakaguchi, Miyuki Sato, Katsuya Sato, Keiko Gengyo-Ando, Tomohiro Yorimitsu Junichi Nakai, Taichi Hara, Ken Sato, Ken Sato. REI-1 is a guanine nucleotide exchange factor regulating RAB-11 localization and function in C. elegans Embryos. e ell 35:211-221(2015)
Miyuki Sato, Ryosuke Konuma, Katsuya Sato, Kotone Tomura, and Ken Sato. Fertilization-induced K63-linked ubiquitylation mediates clearance of maternal membrane proteins. e elopment 141:1324-1331(2014)
Keiko Saegusa, Miyuki Sato, Katsuya Sato, Junko Nakajima-Shimada, Akihiro Harada, Ken Sato. Caenorhabditis elegans chaperonin CCT/TRiC is required for actin and tubulin biogenesis and microvillus formation in intestinal epithelial cells. ol iol ell. 25:3095-104(2014).
Miyuki Sato and Ken Sato. Maternal inheritance of mitochondrial DNA by diverse mechanisms to eliminate paternal mitochondrial DNA. BBA Mol. ell es. 833: 1979-1984(2013)
Miyuki Sato and Ken Sato. Dynamic regulation of autophagy and endocytosis for cell remodeling during early development.
raffic 14:479-486(2013)
Miyuki Sato and Ken Sato. Degradation of paternal mitochondria by fertilization-triggered autophagy in C. elegans embryos. Science 334:1141-1144(2011)
① キヌレン酸の細胞内における生理機能の解析 キヌレン酸は単細胞生物である出芽酵母でも生合成されていますが、細胞内における生理機能は不明です。そこで、出芽酵母の遺伝学的にキヌレン酸を生合成できない株を利用して、細胞内でキヌレン酸が果たす役割の解明に取り組んでいます (図2)。
② キヌレン酸合成酵素の解析 キヌレン酸は生体機能の調節に関わる化合物であり、その合成は厳密に制御されているはずです。そこで、キヌレン酸を合成するキヌレニンアミノトランスフェラーゼの活性制御機構を明らかにするために、本酵素を単離精製し、その生化学的解析を行います (図3)。
主要論文
1) Kazuto Ohashi, Shigeyuki Kawai, and Kousaku MurataSecretion of Quinolinic Acid, an Intermediate in the Kynurenine Pathway, for Utilization in NAD+
Biosynthesis in the Yeast Saccharomyces cerevisiae.
ukaryotic ell 12, 648-653(2013)
Specific aimsynurenic acid is a tryptop an meta olite and is
produced y ynurenine aminotransferases s interacts it cell surface receptors G R and
N met yl aspartate receptor ltered level of is associated it type dia etes and depression I aim to elucidate an intracellular function and meta olism of lso I e pect t at my findings may contri ute to understanding of t ese diseases
▶On-going projects) ysiological roles of is produced from acteria to uman o ever its p ysiological function remains poorly understood I ill study t e importance of in cell meta olism and p ysiology using engineered yeast cells deleted for s
) Regulation mec anisms of s Considering t e ioregulatory functions of t e activity of s s ould e controlled strictly I investigate t e en ymatic properties of s to understand t e regulat ion mec anisms of synt esis
Selected ublication1) Kazuto Ohashi, Shigeyuki Kawai, and Kousaku MurataSecretion of Quinolinic Acid, an Intermediate in the Kynurenine Pathway, for Utilization in NAD+
Biosynthesis in the Yeast Saccharomyces cerevisiae.
ukaryotic ell, 12, 648-653(2013)
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研究スタッフ Staff
未来先端研究機構
細胞シグナル分野 准教授吉田 知史助教高稲 正勝技術補佐員北山 美代子
Associate ProfessorSatoshi Yoshida
Assistant ProfessorMasakatsu Takaine
Assistant TechnicianMiyoko Kitayama
図1 図2
図3 図4
36
Gunma University Initiative for Advanced Research(GIAR)
Specific aimsur la aims to understand molecular mec anism y ic cells respond to e tracellular and intracellular
signals e ta e multifaceted approac com ining ioc emistry Genetics and Imaging to reveal
mec anisms of action of ey signaling molecules suc as smal l G ases prote in inases and p osp atases
▶On-going projects① mec anism y ic m RC activates R o G ase upon mem rane stress
② o does ds protein inactivate p osp atase upon stress
③Identification of a sensor molecule for intracellular p osp ate concentrat ion and def in ing a ro le of polyp osp ates in cellular energetics
最近の研究成果Jonasson EM, Rossio V, Hatakeyama R, Abe M, Ohya Y, Yoshida S.Zds1/Zds2-PP2ACdc55 complex specifies signaling output from Rho1 GTPase.J Cell Biol. 212(1).(2016)
Takaine M, Numata O, Nakano K. An actin‒myosin-II interaction is involved in maintaining the contractile ring in fission yeastJ Cell Sci. 128(15).(2015)
Takaine M, Imada K, Numata O, Nakamura T, Nakano K. The meiosis-specific nuclear passenger protein is required for proper assembly of forespore membrane in fission yeast.J Cell Sci 127.(2014)
Rossio V, Michimoto T, Sasaki T, Ohbayashi I, Kikuchi Y,⦆Yoshida S. Nuclear PP2A-Cdc55 prevents APC-Cdc20 activation during the Spindle assembly checkpoint(SAC)J Cell Sci. 126.(2013)
Atkins BD,⦆Yoshida S, Saito K, Wu CF, Lew DJ, Pellman D. Inhibition of Cdc42 during mitotic exit is required for cytokinesis. J Cell Biol. July 22;202(2).(2013)
Dotiwala F, Eapen VV, Harrison JC, Arbel-Eden A, Ranade V,⦆Yoshida S, Haber JE. The DNA damage checkpoint triggers autophagy to regulate the initiation of anaphase. PNAS.110(1).(2013)
Kono K, Saeki Y,⦆Yoshida S, Tanaka K, Pellman D.Proteasomal Degradation Resolves Competition between Cell Polarization and Cellular Wound HealingCell. 150(1).(2012)
Ikui AE, Rossio V, Schroeder L,⦆Yoshida S. A yeast GSK-3 kinase Mck1 promotes Cdc6 degradation to inhibit DNA re-replication. PLoS Genet. 8(12).(2012)
Rossio V, Yoshida S.Spatial regulation of Cdc55-PP2A by Zds1/Zds2 controls mitotic entry and mitotic exit in budding yeast.J Cell Biol. 2;193(3).(2011)